<meta charset="utf-8">
(#) Allowing User Certificates

!!! WARNING: Allowing User Certificates
   This is a warning.

Id
:   `AcceptsUserCertificates`
Summary
:   Allowing User Certificates
Severity
:   Warning
Category
:   Security
Platform
:   Android
Vendor
:   Android Open Source Project
Feedback
:   https://issuetracker.google.com/issues/new?component=192708
Since
:   3.6.0 (February 2020)
Affects
:   Resource files
Editing
:   This check runs on the fly in the IDE editor
See
:   https://goo.gle/AcceptsUserCertificates
See
:   https://developer.android.com/training/articles/security-config#TrustingDebugCa
Implementation
:   [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/NetworkSecurityConfigDetector.java)
Tests
:   [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/NetworkSecurityConfigDetectorTest.java)

Allowing user certificates could allow eavesdroppers to intercept data
sent by your app, which could impact the privacy of your users. Consider
nesting your app's `trust-anchors` inside a `<debug-overrides>` element
to make sure they are only available when `android:debuggable` is set to
`true`.

(##) Example

Here is an example of lint warnings produced by this check:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text
res/xml/network_config.xml:6:Warning: The Network Security Configuration
allows the use of user certificates in the release version of your app
[AcceptsUserCertificates]
    &lt;certificates src="user"/&gt;
    --------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Here is the source file referenced above:

`res/xml/network_config.xml`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers
&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;network-security-config&gt;
    &lt;base-config&gt;
        &lt;trust-anchors&gt;
            &lt;certificates src="system"/&gt;
            &lt;certificates src="user"/&gt;
        &lt;/trust-anchors&gt;
    &lt;/base-config&gt;
&lt;/network-security-config&gt;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You can also visit the
[source code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/NetworkSecurityConfigDetectorTest.java)
for the unit tests for this check to see additional scenarios.

The above example was automatically extracted from the first unit test
found for this lint check, `NetworkSecurityConfigDetector.testAllowsUserCertificates`.
To report a problem with this extracted sample, visit
https://issuetracker.google.com/issues/new?component=192708.

(##) Suppressing

You can suppress false positives using one of the following mechanisms:

* Adding the suppression attribute
  `tools:ignore="AcceptsUserCertificates"` on the problematic XML
  element (or one of its enclosing elements). You may also need to add
  the following namespace declaration on the root element in the XML
  file if it's not already there:
  `xmlns:tools="http://schemas.android.com/tools"`.

* Using a special `lint.xml` file in the source tree which turns off
  the check in that folder and any sub folder. A simple file might look
  like this:
  ```xml
  &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;lint&gt;
      &lt;issue id="AcceptsUserCertificates" severity="ignore" /&gt;
  &lt;/lint&gt;
  ```
  Instead of `ignore` you can also change the severity here, for
  example from `error` to `warning`. You can find additional
  documentation on how to filter issues by path, regular expression and
  so on
  [here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html).

* In Gradle projects, using the DSL syntax to configure lint. For
  example, you can use something like
  ```gradle
  lintOptions {
      disable 'AcceptsUserCertificates'
  }
  ```
  In Android projects this should be nested inside an `android { }`
  block.

* For manual invocations of `lint`, using the `--ignore` flag:
  ```
  $ lint --ignore AcceptsUserCertificates ...`
  ```

* Last, but not least, using baselines, as discussed
  [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).

<!-- Markdeep: --><style class="fallback">body{visibility:hidden;white-space:pre;font-family:monospace}</style><script src="markdeep.min.js" charset="utf-8"></script><script src="https://morgan3d.github.io/markdeep/latest/markdeep.min.js" charset="utf-8"></script><script>window.alreadyProcessedMarkdeep||(document.body.style.visibility="visible")</script>